Download or read book Mid infrared Laser Absorption Spectroscopy for Carbon Oxides in Harsh Environments written by R. Mitchell Spearrin and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Advancements in measurement science are presented regarding in situ laser-based detection of CO and CO2 in harsh combustion environments. Mid-infrared absorption sensing strategies, utilizing transitions in the 2.7 and 4.3 micron vibrational bands for CO2 and the 4.8 micron vibrational band for CO, were developed to enable sensitive measurements of temperature and carbon oxide concentrations in high-temperature gases. These new strategies (1) extend the utility of carbon oxide absorption sensing for hostile aeroengine applications and (2) offer significant improvements to previous methods for shock tube kinetics studies. The recent maturation of mid-infrared diode and quantum cascade lasers, combined with parallel progress in mid-infrared fiber optics, provides the platform from which the field-deployable sensors were designed. State-of-the art signal processing strategies, including calibration-free wavelength modulation spectroscopy, were implemented to tackle the thermo-mechanically harsh environments of a pulse detonation combustor and directconnect scramjet. Time-resolved and spatially-resolved measurements of temperature and carbon oxide species concentrations were demonstrated to provide an in situ metric to evaluate combustion completion for engine development. For shock tube kinetics studies, a multi-band CO2 sensing strategy was developed to provide ppm-level species detection and highly-sensitive measurements of gas temperature with microsecond temporal resolution.
Download or read book Development of Laser Absorption Sensors for Combustion Gases written by Xing Chao and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In situ sensors based on laser absorption spectroscopy are developed to monitor key species in combustion exhaust gases. Direct absorption (DA) and wavelength-modulation-spectroscopy (WMS) strategies are investigated for extended near-infrared and mid-infrared laser devices to detect target species in harsh environments at combustion exhaust temperatures in the presence of high moisture level and heavy particulate loading. A real time, in situ sensor for carbon monoxide (CO) was developed using DFB diode lasers near 2.3 æm, with selected transitions (R(10) near 4297.7 cm-1, R(11) near 4300.7 cm-1) in the first overtone band of CO. The sensor was studied in the controlled laboratory environments of a heated cell and a combustion exhaust rig. High temperature water vapor absorption spectra were first measured, and shown to produce
Download or read book High Resolution Infrared Spectroscopy of Carbon Dioxide and Nitrous Oxide at Elevated Temperatures written by Mark P. Esplin and published by . This book was released on 1988 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although both Carbon Dioxide and Nitrous Oxide are minor constituents of the terrestrial atmosphere, they play leading roles in several current atmospheric problems. Both CO2 and N2O are greenhouse gases, and while it is known that the atmospheric concentrations of both gases is increasing, the impact of these trends on global temperature is not yet adequately understood. In addition to being a greenhouse gas, N2O plays an indirect part in ozone chemistry. Heating a molecule makes possible the observations of molecular transitions originating from highly excited rotation-vibration states. Heating a molecule makes possible the observations of molecular transitions originating from highly excited rotation-vibration states. These observations can then be used to characterize the shape of the molecular potential function at increasing distances from the minimum of the potential function. The infrared spectra of linear molecules like CO2 and N2O are composed of vibration bands made up of a number of nearly equally spaced rotation lines. A Fourier Spectrometer is ideally suited to the study of high temperature gases since it meets both of these needs by providing high resolution over a wide spectral region.
Download or read book Tunable Diode Laser Infrared Reflection Absorption Spectroscopy of Carbon Monoxide on Pt 111 written by Leyla F. Sutcu and published by . This book was released on 1990 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Infrared Absorption Spectrum of Carbon Monoxide written by Erwin Foster Lowry and published by . This book was released on 1923 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopy and Optical Diagnostics for Gases written by Ronald K. Hanson and published by Springer. This book was released on 2015-10-26 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides an introduction to the science that governs the interaction of light and matter (in the gas phase). It provides readers with the basic knowledge to exploit the light-matter interaction to develop quantitative tools for gas analysis (i.e. optical diagnostics) and understand and interpret the results of spectroscopic measurements. The authors pair the basics of gas‐phase spectroscopy with coverage of key optical diagnostic techniques utilized by practicing engineers and scientists to measure fundamental flow‐field properties. The text is organized to cover three sub‐topics of gas‐phase spectroscopy: (1) spectral line positions, (2) spectral line strengths, and (3) spectral lineshapes by way of absorption, emission, and scattering interactions. The latter part of the book describes optical measurement techniques and equipment. Key subspecialties include laser induced fluorescence, tunable laser absorption spectroscopy, and wavelength modulation spectroscopy. It is ideal for students and practitioners across a range of applied sciences including mechanical, aerospace, chemical, and materials engineering.
Download or read book Infrared Laser Absorption Spectroscopy of Nitric Oxide for Sensing in High enthalpy Air written by Christopher Andrew Almodovar and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Motivated by thermometry in high-enthalpy air, advancements towards the measurement and modeling of high-pressure laser absorption spectroscopy (LAS) of nitric oxide (NO) are presented. The primary application of this thermometer is to characterize the stagnation conditions (T = 1000--2500 K and P = 10--130 atm) in a clean-air hypersonic wind tunnel facility. By characterizing the thermodynamic conditions upstream of the expansion nozzle, the flow conditions of the expanding air can be determined via enthalpy matching. At high temperatures, the Zeldovich mechanism describes increasing NO formation in air with increasing temperature, making NO an attractive species for LAS-based temperature measurements in air. Two optical transitions in the R-branch of the fundamental rovibrational band of NO are selected and their fundamental spectroscopic parameters are characterized at high temperatures. The temperature sensor design is demonstrated in reflected shock wave experiments in a large diameter shock tube at pressures up to 5 atm. Although the target application's operating pressure range is well outside the demonstration range, the fundamental concept of two-wavelength absorption is still valid. However, at high pressures, the selected optical transitions begin to blend with their neighboring transitions. Thus, accurate knowledge of the high-temperature and high-pressure absorption at the selected wavelengths requires knowledge of the spectroscopic parameters defining the neighboring transitions. To measure the spectroscopic parameters of the many neighboring transitions, a high-pressure, high-temperature (HPHT) optical cell (up to 800 K and over 30 atm) is designed and demonstrated for mid-infrared spectroscopy with usable transmission up to approximately 8 microns. With a functional HPHT optical cell, a detailed, temperature-dependent study (up to 800 K) of the optical transitions in the NO R-branch near 5.3 microns is performed. To extend the study to temperatures relevant for the target sensing application, shock tube measurements from 1000 to 2500 K supplement the detailed study. Finally, the spectrum is studied at high pressures. Static cell measurements reveal deviations from the classical line shape models used accurately at low pressures. The deviations are attributed to collisional line mixing that emerges when the line widths of the optical transitions are of similar or greater magnitude than the separation of optical transitions. A temperature-dependent line mixing model is built using statistically-based energy gap fitting laws and the full relaxation matrix expression. A comparison with measured data reveals good agreement in the regions where inter-branch coupling can be neglected. In the end, a thorough treatment of the NO spectrum has provided a temperature- and pressure-dependent model that can be used to predict the absorption spectra of NO in the R-branch of the fundamental rovibrational band.
Download or read book Infrared Absorption Spectrum of Carbon Dioxide written by Paul Edmond Martin and published by . This book was released on 1932 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Line Mixing Studies of Diatomic Rovibrational Fundamental Bands in the Infrared written by Dean W Su and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser absorption spectroscopy enables quantitative, non-intrusive, and short-time-scale measurements of gaseous systems, especially at extreme temperature and pressure conditions where traditional sensors may fail. As we develop more powerful energy systems and optical metrology facilities, the need for accurate sensing in these extreme conditions has grown to include studies of combustion systems, propulsion facilities, and more recently, even exoplanetary bodies in space. Unfortunately, at higher pressure conditions, collisional "line mixing" effects cause the traditional absorption models that inform most absorption-based sensing techniques to fail. The characterization and modeling of these line mixing effects are therefore important to maintain accurate sensing across environments of interest. This dissertation will focus on the experimental measurement and modeling of broadband mid-infrared light absorption across elevated pressure and temperature conditions, especially where collisional line mixing effects are significant. In this work, I present quantitative, broadband absorbance measurements of the fundamental rovibrational band of carbon monoxide (CO) between 1965 and 2230 cm-1 in bath gases of nitrogen (N2), helium (He), and hydrogen (H2), and nitric oxide (NO) between 1700 to 2000 cm-1 in N2. These measurements were taken using a static cell and a narrow-linewidth, broad-scan external-cavity quantum-cascade laser at pressures of 15-35 atm and temperatures of 293, 453 (CO/H2) and 802 K (CO/N2, CO/He, NO/N2). The measurements are then compared to multiple constructed models capable of reproducing the effects of line mixing present in the measured results. The first line mixing approach, based on the modified exponential gap (MEG) law with fitted inter-branch factors, shows improved agreement with the measured spectra across different pressures and broadening partners relative to purely Lorentzian models. The NO model required two fitted inter-branch factors to achieve satisfactory agreement, necessary due to its additional Q-branch structure relative to that of CO. At the elevated temperatures, similar agreement is observed; however, for CO, a mismatch is present between extrapolated HITRAN broadening parameters and those observed in the measured spectra. This is likely due to the known deficiency of the single power law over large temperature ranges, and hence a minor scaling of the line-by-line temperature-dependence exponents is incorporated that is supported by previous studies in the literature. The second, more empirical line mixing approach involves extracting MEG line mixing parameters through a direct fit to the measured spectra. The Direct Fit method bypasses the need for known line shape parameters and produces even stronger agreement with measured CO data, with a CO/H2 root-mean-square error of 0.4% at the highest-number-density condition of 293K and 35atm. This approach is slightly less effective for modeling NO due to its additional spin-split lines, but satisfactory agreement is still demonstrated with constraints placed on the spin-split MEG parameters. Finally, the last line mixing approach utilizes the Energy Corrected Sudden (ECS) scaling law, which eliminates the need for any additional fitted factors, and produces reasonable agreement across the measured NO spectra, excluding the Q-branch. In the NO Q-branch peak, the ECS model overpredicts the measured data by about 7%, possibly due to the presence of additional collisional coupling between the NO spin-split lines. The line mixing models presented will be useful across a number of applications, from accurate NO thermometry in hypersonic propulsion test facilities on the ground to the interpretation of future infrared observations of CO in exoplanetary gas giant atmospheres deep in space.
Download or read book Green Electronics written by Cristian Ravariu and published by BoD – Books on Demand. This book was released on 2018-06-20 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Green Electronics book is intended to stimulate people's thinking toward the new concepts of an environment-friendly electronics - the main challenge in the future. The book offers multiple solutions to push the classical electronic industry toward green concepts, aided by nanotechnologies, with revolutionary features that provide low power consumption in electronics, use biomaterials for integrated structures, and include environmental monitoring tools. Based on organic semiconductors/insulators without toxic precursors, green electronic technologies launched promising devices like OLED, OTFT, or nano-core-shell transistors. The Green Electronics book successfully presents the recent directions collected worldwide and leaves free space for continuing year by year with new subtopics.
Download or read book Laser Absorption Spectroscopy Techniques for Determining Gas Properties in High Pressure Rocket Combustors written by Daniel D Lee and published by . This book was released on 2020 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes laser absorption spectroscopy methods developed for temperature and carbon oxide (CO and CO2) sensing in high-pressure, fuel-rich combustion conditions of hydrocarbon-fueled bipropellant rockets. The scope of the work includes fundamental studies of spectroscopic interactions at high gas density, development of unique laser tuning and signal processing methods, and application of prototype sensors to rocket combustion devices under investigation at the Air Force Research Laboratory in Edwards, CA. Infrared vibrational spectra of CO and CO2 were probed using tunable semi-conductor lasers to infer gas properties. Initial sensor design targeted the absorption spectra of CO near 4.98 m, selected to minimize spectral interference with other combustion gas species at the extreme temperatures (> 3000 K) and pressures (> 50 atm) of a kerosene-fueled rocket combustion environment. Successful measurements were conducted up to 70 bar utilizing a scanned wavelength modulation spectroscopy technique, creating a new pressure-limit for quantitative in situ species sensing in a combustion device. At higher pressures (which were tested), collisional-broadening effects blended the targeted absorption transitions, causing differential absorption to diminish and reducing the signal-to-noise ratio of the measurements. To overcome the pressure-constraints, a more advanced laser absorption sensing strategy was developed, targeting the vibrational bandheads of CO near 2.3 m and CO2 near 4.2 m and exploiting the band narrowing effects of collisional line mixing to counter collisional broadening. Spectral line mixing--typically observed at high gas densities in which intermolecular collisions are sufficiently frequent and strong to cause a shift in energy level populations--corresponds to a transfer of absorption intensity from weak to strong absorption regions, inducing a narrowing of spectral features. This non-ideal phenomenon is more prominent in spectrally dense regions, such as bandheads. Targeting infrared bandheads to exploit line mixing, measurements of CO and CO2 concentration were demonstrated over a range of high pressures up to 105 bar in a single-element-injector RP-2/CH4-GOx rocket combustor. To make such measurements quantitative,spectroscopic models accounting line mixing effects have been developed utilizing a high-enthalpy shock tube; these models are then employed for interpretation of measured absorption signals for quantitative temperature and species sensing.
Download or read book Temperature Compensated High Resolution Infrared Absorption Spectroscopy Application to Carbon Monoxide written by C. J. Fisher and published by . This book was released on 1981 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analytic basis of an optical absorption technique suitable for a single line-of-sight determination of average gaseous species number densities in the presence of concentration, pressure and temperature gradients, and particulate loading is presented and applied to carbon monoxide (CO). Applying the technique involves using the power of very high-resolution infrared (IR) spectroscopy, now made available by tunable diode lasers. The method requires the construction of functions of molecular line strengths that are nearly temperature independent. A method of constructing these functions is described and applied to the case of CO. Possible applications to practical combustion systems are also outlined. (Author).
Download or read book Carbon Dioxide Sensing written by Gerald Gerlach and published by John Wiley & Sons. This book was released on 2019-08-05 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides the reader with a profound knowledge of basic principles, properties and preferred applications of diverse kinds of CO2 measurement. It shows the advantages, disadvantages and limitations of several methods and gives a comprehensive overview of both possible applications and corresponding boundary conditions. Applications reach from environmental monitoring to safety control to biotechnology and food control and finally to medicine.
Download or read book Direct Infrared Laser Absorption Spectroscopy of Jet cooled Carbon and Silicon carbon Clusters written by Alan K. Van Orden and published by . This book was released on 1996 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Infrared Reflection absorption Spectroscopy for Carbon Monoxide Chemisorbed on Platinum Foil written by Juris Imants Apse and published by . This book was released on 1973 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Industrial Tomography written by Mi Wang and published by Woodhead Publishing. This book was released on 2022-05-07 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt: Industrial Tomography: Systems and Applications, Second Edition thoroughly explores the important techniques of industrial tomography, also discusses image reconstruction, systems, and applications. This book presents complex processes, including the way three-dimensional imaging is used to create multiple cross-sections, and how computer software helps monitor flows, filtering, mixing, drying processes, and chemical reactions inside vessels and pipelines. This book is suitable for materials scientists and engineers and applied physicists working in the photonics and optoelectronics industry or in the applications industries. Provides a comprehensive discussion on the different formats of tomography, including advances in visualization and data fusion Includes an excellent overview of image reconstruction using a wide range of applications Presents a comprehensive discussion of tomography systems and their applications in a wide variety of industrial processes
Download or read book Photonic Applications for Aerospace Transportation and Harsh Environments written by Anbo Wang and published by SPIE-International Society for Optical Engineering. This book was released on 2006 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.
